Note 7 - Comprehensive (Loss) Income - Accumulated Other Comprehensive (Loss) (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022
Balance	$ 1,224,227	$ 1,216,609	$ 1,216,620	$ 1,199,397	$ 1,190,970	$ 1,178,751
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]
Balance	(70,064)		(57,835)
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Balance	29,842		24,810
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balance	(2,022)		(2,084)
AOCI Attributable to Parent [Member]
Balance	$ (42,244)	$ (38,132)	$ (35,109)	$ (33,837)	$ (33,862)	$ (32,364)